feat(resolvemcp): replace per-model tools with fixed meta tools, guarded filter writes and a function registry

Tools: list_tables, describe_table, select_table, insert_into_table, update_table,
delete_from_table, list_functions, call_function. Visibility follows the model rules.
Filter-based update/delete require filters (never dropped silently), cap the matched rows
(MaxWriteRows), support dry_run, and need a single-use confirm token bound to caller, table,
filters, data and the matched rows. RegisterFunction adds Go-callback and SQL-procedure
functions run in a transaction with BeforeCall/AfterCall hooks. Per-model tools and
resources are removed.

fix(pgsql): UPDATE with SET and a multi-placeholder WHERE renumbered the WHERE parameters
wrongly ($1, $2 became $3, $2); shift them in one pass.

pkg/common/tx_guard_test.go

@@ -27,12 +27,13 @@ var allowedPoolHookTx = map[string]int{
 	"resolvespec/handler.go":   1,
 	"websocketspec/handler.go": 1,
 	"resolvemcp/handler.go":    4,
+	"resolvemcp/annotation.go": 1, // BeforeHandle context of the annotate tool
+	"resolvemcp/writewhere.go": 1, // BeforeHandle context of filter writes
+	"resolvemcp/functions.go":  1, // BeforeHandle context of call_function
 }
 
 // allowedPoolQuery: statements outside the request path.
-var allowedPoolQuery = map[string]int{
-	"resolvemcp/annotation.go": 2, // tool annotations, not a data request
-}
+var allowedPoolQuery = map[string]int{}
 
 func guardedFiles(t *testing.T) map[string][]string {
 	t.Helper()